Timeline by Djordje Djukic, with additional reporting by Evan Centanni

Houthi Control Spreading Despite Saudi Airstrikes
Since our previous Yemen control map update in early April, Saudi Arabia and its coalition partners have continued their air and sea campaign in support of the ousted Yemeni government of President Abd Rabbuh Mansur Hadi, supported by parts of the Yemeni military and allied local and southern forces. But two months into the intervention, their opponents, the northern Houthi rebels and forces loyal to former president Ali Abdullah Saleh, have continued to expand eastward. Meanwhile, Al Qaeda fighters have consolidated their control in parts of eastern Yemen, and the port city of Aden is still divided by frequent battles.

Chronology of Events
The following is a timeline of major political events and changes to territorial
control since PolGeoNow's April 3 Yemen control map report.

April 4, 2015
Hadi troops, reinforced by Saudi weapons drops, pushed back the Houthis from the Crater district in Aden.

April 5, 2015The Houthis advanced into the central Mualla district of Aden, capturing the provincial headquarters. Also, fighting in the Houthi-held city of Lawdar (Loder) left 24 people dead, including 21 Shiite militiamen.

April 7, 2015
The Hadhramout Tribal Alliance and pro-Hadi militiamen claimed to recapture Mukalla from Al Qaeda in the Arabian Peninsula (AQAP), but residents reported Al Qaeda was still in control of around half of the town. In addition, AQAP militants captured Wadiah border crossing with Saudi Arabia, killing two soldiers.

April 9, 2015
Houthi and allied forces captured Ataq, the provincial capital of Shabwah Governorate, after a deal was reached with local leaders and security officials

April 14, 2015
The UN Security Council passed a resolution for an arms embargo to be applied to the Houthis and their allies, with 14 in favor and Russia abstaining, after its request for the embargo to include all parties to the conflict was refused. The same day, the Houthis retreated from Aden’s Khor Maksar district after prolonged street fighting.

April 16, 2015
Al Qaeda sized the Riyan airport and Mukalla's seaport and oil terminal, with the main government brigade responsible for security fleeing after a brief clash with the militants outside the city. In addition, the fighters captured a massive weapons depot that contained dozens of tanks, Katyusha rocket launchers and small arms. With this advance, Al Qaeda consolidated its hold on Hadhramaut province, and is believed to be back in control of most of Mukalla.

April 17-18, 2015
Houthi and allied forces attacked the base of the 35th Armored Brigade in Taiz, Yemen's third largest city, after the brigade announced its loyalty to Hadi.

April 21, 2015
Saudi Arabia declared an end to its “Decisive Storm” air campaign, saying it would scale down the airstrikes at the request of President Hadi, but not claiming it would stop them altogether. Instead, a more limited military campaign was announced and named “Renewal of Hope”, with the stated aim of preventing the Houthis from targeting civilians or making any territorial gains.

April 23, 2015
The Saudi-led Coalition conducted 20 air-strikes against Houthi targets, despite saying earlier that it was winding down the campaign.

April 25, 2015
Heavy fighting took place in Marib province as pro-Houthi forces attempted to advance into the Sirwah district. Four days earlier, a local pro-Hadi official claimed that between April 2 and 22, 150 pro-Houthi and 27 anti-Houthi fighters had been killed in clashes in the province.

April 28, 2015A Houthi counter-attack resulted in the recapture of the Russian and German consulates and Hadi’s residence in Aden, after advances in the Khor Maksar district, and pro-Houthi forces to the north of the city made a push to the west in an attempt to recapture territory previously lost.

April 29, 2015
Houthi fighters advanced into the center of Aden, taking territory from the Russian consulate to the Crater business district, and were once again largely in control of the city’s airport. Houthi forces also repelled pro-Hadi counterattacks in the Khor Maksar and Mualla districts of the city. According to Aden's health ministry, 375 civilians had been killed and 2,500 wounded since the battle began.

May 3, 2015
Twenty soldiers, initially described as members of the Saudi-led coalition, reportedly landed in Aden on a reconnaissance mission. Another account put the number of soldiers at 50, while Saudi Arabia denied any ground troops were sent to Yemen. The next day, the unidentified soldiers reportedly took part in fighting near the Aden airport, with pro-Hadi forces storming parts of the facility, while a spokesman for the allied Southern Popular Resistance retracted an earlier statement that the soldiers were part of the coalition, instead saying they were homegrown special forces from the south. Later, the pro-Hadi Yemeni foreign minister stated the soldiers were members of the pro-Hadi government forces who had been sent to Gulf countries to be trained before returning to Yemen.

May 7, 2015
Saudi Arabia and the United States declared a five-day ceasefire to allow aid to enter Yemen, while the UN humanitarian coordinator stated more than 1,400 people had been killed and 6,000 injured in the conflict since March 26.

May 11, 2015A Moroccan fighter jet belonging to the Saudi-led coalition went missing, along with its pilot, in Yemen, and was possibly shot down by Houthi forces. At the same time, one person was killed in a Saudi town, close to the Yemeni border, by Houthi shelling. This brought the overall death toll from Houthi cross-border rocket and mortar attacks, which started the previous week, to 11.

May 12, 2015
The five-day ceasefire commenced in the evening, but some ground fighting continued.

June 4, 2015
According to the United Nations, the death toll from the conflict since March 19, up to May 31, reached 2,288. Another 9,755 people were wounded. Of the casualties, 1,160 of the dead were civilians, as were over 2,800 of those injured.

June 5, 2015
The Houthis and the Hadi government agreed to attend UN-brokered peace talks in Geneva.

June 6, 2015
Saudi Arabia shot down a Scud missile fired from Yemen toward a military base in southwestern Saudi Arabia. The Scud was brought down using a US-supplied Patriot surface-to-air missile defense system.

June 12, 2015UNESCO condemned a Saudi airstrike on the old quarter of Yemen’s capital, a centuries-old heritage site considered a “jewel” of Islamic culture. The attack killed five people and destroyed several homes.

June 13, 2015
The Houthi rebel delegation, which was supposed to attend peace talks with the Hadi government, refused to board the plane for Geneva. The reason given was that the Houthis objected to there being two separate delegations in Geneva - one representing the Hadi government and the second (the Houthis) being seen as representing a “coup”. According to a Houthi representative, this was meant to pressure the Houthis to withdraw from Sana'a and did not foster an environment suitable for the continuation of broader multi-party talks.

June 14, 2015
Houthi and pro-Saleh Army forces captured Al Hazm, the capital of Jawf province, which includes much of the border with Saudi Arabia.

June 19, 2015
The peace negotiations in Geneva ended without an agreement, but UN envoy Ismail Ould Cheikh Ahmed was optimistic that in a matter of time a ceasefire could be reached under which the rebels would withdraw from towns they had seized in the previous months, with both sides seeming supportive of the plan.